Deoxidizing multilayered body

ABSTRACT

The present invention provides a deoxidizing multilayered body, which sufficiently suppresses the production of odorous organic components produced by oxidation, and which absorbs oxygen at a fast rate. 
     The present invention relates to the deoxidizing multilayered body that is constituted by laminating at least an isolation layer (A) that contains a thermoplastic resin, an oxygen absorption layer (B) which is made of an oxygen absorbent resin composition (b) that contains an oxidizable thermoplastic resin and a transition metal catalyst, an odor absorption layer (C) which is made of an odor absorbent resin composition (c) that contains a thermoplastic resin and an odor absorbent, and an oxygen barrier layer (D) which contains an oxygen barrier substance, in this order.

TECHNICAL FIELD

The present invention relates to a deoxidizing multilayered body. Thedeoxidizing multilayered body of the present invention can be used for apart or whole of a deoxidizing container, sheet, or film.

In the present specification, the term “deoxydize” means that the oxygenconcentration becomes 0.1 vol % or less under a sealed environment andthe term “deoxygenizer” means a chemical agent, a material, and the likewhich are used for the purpose of achieving a deoxygenated state.Further, the term “deoxidizing” has the same meaning as the expression“has a function of a deoxygenizer.” Still further, the term “absorboxygen” means that the chemical agent, material, and the like take inthe oxygen contained in the environment regardless of the reached oxygenconcentration.

BACKGROUND ART

For the purpose of preserving for a long period of time the variousproducts that are prone to deteriorate or degrade under the influence ofoxygen, and that are represented by food products, beverages,pharmaceuticals, medical products, cosmetics, metal products, andelectronic products by preventing their oxidation by oxygen, adeoxygenizer which eliminates oxygen contained in a packaging containeror a packaging bag storing such products has been used. The shape whichhad been developed at early stage and still used commonly as thedeoxidizer is a shape in which a deoxygenizer consisting of powdery orgranular iron powder, ascorbic acid, or the like is filled in anair-permeable sache.

In recent years, film type deoxygenizers having good handleability, wideapplication range, and very little possibility of accidental ingestionare also being used. With respect to the film type deoxygenizer, varioussuggestions have been made in terms of an oxygen absorbent compositionand a film constitution. A basic deoxidizing multilayered body is known,that is obtained by adding a deoxygenizer like iron powder or ascorbicacid, etc. to a resin, molding the resin into a film, a sheet, or thelike, laminating an isolation layer having heat sealability on one side,and laminating a gas barrier layer on the other side (Patent Document1). Further, a packaging film containing a layer made from oxidizableorganic components or resin components and a transition metal catalystis also known (Patent Documents 2 and 3). In addition, for the purposeof suppressing odor produced by a deoxidizer consisted of an organicmaterial with the oxidation, including an adsorbent like zeolite, etc.in an oxygen absorbent composition, preparing a deoxidizing multilayeredfilm which is obtained by laminating layers containing an adsorbent, orpreparing a deoxidizing multilayered film which is obtained bylaminating layers containing a base as a neutralizing agent of an acidicgas causing odor has been suggested (Patent Documents 4 to 6).

Furthermore, as an agent for eliminating aldehyde-based gas causingunpleasant smell mainly for the purpose of the elimination of tobaccosmell and a counter measure against a sick building syndrome, an aminecompound, a hydrazide compound, or a hydrazine derivative supported onan inorganic material is known (Patent Documents 7 and 8).

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No.55-90535

Patent Document 2: Japanese Patent No. 2991437

Patent Document 3: Japanese Patent No. 3183704

Patent Document 4: JP-A No. 05-247276

Patent Document 5: JP-A No. 06-100042

Patent Document 6: Japanese Patent No. 3306071

Patent Document 7: Japanese Patent No. 2837057

Patent Document 8: JP-A No. 2007-204892

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The inventors of the present invention found the following problems.

More specifically, as described above, the deoxidizing multilayered filmwhich contains an oxygen absorption layer made from oxidizable organiccomponents or resin components and a metal catalyst is problematic inthat odorous organic components are produced with oxidation of theorganic components or the resin components during deoxygenation process.In particular, when the deoxidizing multilayered film is used forpackaging food products, flavor of the food products are impaired evenby production of weak odor, coming up a significant problem of loweringthe value of the food products.

Thus, an object of the present invention is to provide a deoxidizingmultilayered body which suppresses the production of odorous componentsproduced with oxidation, and can absorb oxygen at a practicallysufficient rate.

Means for Solving the Problems

The inventors of the present invention conducted a research on adeoxidizing multilayered body, and as a result, found that by laminatingan odor absorption layer containing an odor absorbent and an oxygenabsorption layer, and laminating an oxygen barrier layer on the odorabsorption layer side and an isolation layer on the oxygen absorptionlayer side, a deoxidizing multilayered body which suppresses theproduction of odorous organic components produced with oxidation and canabsorb oxygen at a practically sufficient rate is obtained, andtherefore accomplished the present invention.

More specifically, the present invention is a deoxidizing multilayeredbody constituted by laminating at least an isolation layer (A) thatcontains a thermoplastic resin, an oxygen absorption layer (B), which ismade of an oxygen absorbent resin composition (b) that contains anoxidizable thermoplastic resin and a transition metal catalyst, an odorabsorption layer (C), which is made of an odor absorbent resincomposition (c) that contains a thermoplastic resin and an odorabsorbent, and an oxygen barrier layer (D), which contains an oxygenbarrier substance, in this order.

Further, in the deoxidizing multilayered body of the present invention,the odor absorbent resin composition (c) is preferably an odorabsorption resin composition (cx) that contains an oxidizablethermoplastic resin, a transition metal catalyst, and an odor absorbent.

Moreover, in the deoxidizing multilayered body of the present invention,the isolation layer (A) is preferably an acidic gas absorbent isolationlayer (Aa), which is made of an acidic gas absorbent resin composition(a) containing an acidic gas absorbent and a thermoplastic resin.

The acidic gas absorbent used in the present invention is preferably abase compound, and particularly preferably magnesium oxide.

The odor absorbent used in the present invention preferably contains ahydrazine derivative, a urea derivative, or a guanidine derivative, andparticularly preferably, it is constituted by having a hydrazinederivative, a urea derivative, or a guanidine derivative supported on acarrier.

Also, it is preferable that the hydrazine derivative is anaminoguanidine derivative and/or a hydrazine double salt.

In the deoxidizing multilayered body of the present invention, aphotoinitiator can be further included in the oxygen absorbent resincomposition (b) and/or the odor absorbent resin composition (cx).

In the deoxidizing multilayered body of the present invention, it ispreferable that the oxygen absorbent resin composition (b) furthercontains at least one component selected from the group consisting of aphotoinitiator, a thermoplastic resin that is different from theoxidizable thermoplastic resin, and an additive, and the totalcompounding ratio of the oxidizable thermoplastic resin, the transitionmetal catalyst, and the component is 100% by mass in the oxygenabsorbent resin composition (b).

Further, the present invention relates to a packaging container having,at least in a part thereof, the deoxidizing multilayered body, which isconstituted by placing the isolation layer (A) on the inside of thecontainer.

Effects of the Invention

According to the present invention, with the deoxidizing multilayeredbody in which a layer made from an oxygen absorbent resin compositioncontaining an oxidizable thermoplastic resin and a transition metalcatalyst is laminated, the problem of odor produced during the processof absorbing oxygen is solved without impairing the oxygen absorptioncapability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an embodiment of a deoxidizingmultilayered body in the present invention.

FIG. 2 is a cross-sectional view of an embodiment of a deoxidizingpackaging container in the present invention.

MODE FOR CARRYING OUT THE INVENTION

Below, embodiments of the present invention will be explained withreference to FIG. 1 and FIG. 2, if necessary. For the identical orequivalent constitutional elements in FIG. 1 and FIG. 2, the identicalletters are given and overlapped explanations are omitted.

An oxygen absorbent resin composition containing an oxidizablethermoplastic resin and a transition metal catalyst produces odorousorganic components as a by-product during the oxidation process.Therefore, a deoxidizing multilayered body constituted by three layersincluding an isolation layer, an oxygen absorption layer in which theoxygen absorbent resin composition containing an oxidizablethermoplastic resin and a transition metal catalyst is used, and anoxygen barrier layer has a problem of by-production of odorouscomponents. To solve this problem, the inventors of the presentinvention conducted various studies as described below, and as a resultaccomplished the present invention, which corresponds to the best mode.

When a thermoplastic resin layer (i.e., odor absorption layer)containing an odor absorbent is laminated between the oxygen absorptionlayer and the isolation layer in the above multilayered body, it becomespossible to suppress the diffusion of the odorous organic componentsfrom the oxygen absorption layer towards the isolation layer side.However, since the odor absorption layer acts as resistance to oxygenpermeation, the oxygen absorption rate was decreased.

Meanwhile, when an odor absorbent is included in the oxygen absorbentresin composition containing an oxidizable thermoplastic resin and atransition metal catalyst, it becomes possible to increase both theoxygen absorption rate and the odor suppressing effect. However, whenthe resin composition is used for the oxygen absorption layer to providea deoxidizing multilayered body which has three layers including anisolation layer, an oxygen absorption layer, and an oxygen barrierlayer, the oxygen absorption rate was significantly decreased althoughthe odor suppressing effect remains.

On the other hand, the deoxidizing multilayered body of the presentinvention is constituted by laminating at least an isolation layer (A),an oxygen absorption layer (B), an odor absorption layer (C) whichcontains an odor absorbent, and an oxygen barrier layer (D) in thisorder, and therefore can suppress odor while keeping high oxygenabsorption capability. Further, by using an oxidizable thermoplasticresin as the thermoplastic resin that is contained in the odor absorbentresin composition (c) constituting the odor absorption layer (C), higheroxygen absorption capability may be obtained. Further, by compounding anacidic gas absorbent in the isolation layer (A) to constitute an acidicgas absorbent isolation layer (Aa), production of an acidic gas can bealso suppressed. Further, a reinforcement layer which is next to aninterlayer region between layers and can increase the strength of thefilm, a recycle layer in which a recovered resin is reused, an adhesivelayer which improves the interlayer strength, etc. can be also laminatedunless it does not impair the effect of the present invention.

Herein below, one embodiment for carrying out the present invention willbe explained in line with the drawings. FIG. 1 is a cross-sectional viewof an embodiment of a deoxidizing multilayered body according to thepresent invention. In FIG. 1, (A) is an isolation layer which contains athermoplastic resin. (B) is an oxygen absorption layer which is made ofan oxygen absorbent resin composition (b) that contains an oxidizablethermoplastic resin and a transition metal catalyst. (C) is an odorabsorption layer which is made of an odor absorbent resin composition(c) that contains a thermoplastic resin and an odor absorbent. Further,(D) is an oxygen barrier layer which contains an oxygen barriersubstance. Further, in FIG. 1, reference 11 represents an odorabsorbent.

The present invention relates to a deoxidizing multilayered bodyconstituted by laminating at least four layers including the isolationlayer (A), the oxygen absorption layer (B), the odor absorption layer(C), and the oxygen barrier layer (D) in this order, and a deoxidizingpackaging container which has, at least in a part thereof, thedeoxidizing multilayered body and is constituted by placing theisolation layer (A) on the inside of the container.

Herein below, the isolation layer (A), the oxygen absorption layer (B),the odor absorption layer (C), and the oxygen barrier layer (D) whichconstitute the deoxidizing multilayered body of the present inventionwill be explained in detail.

[Isolation Layer (A)]

The isolation layer (A) which constitutes the deoxidizing multilayeredbody of the present invention plays a role of separating a storedproduct from the oxygen absorption layer (B), and at the same time itfunctions as a sealant. Further, it also plays a role of performingefficient oxygen permeation not to prevent the fast oxygen absorption bythe oxidizable thermoplastic resin contained in the oxygen absorbentresin composition (b), which constitutes the oxygen absorption layer(B).

The isolation layer (A) of the present invention means a layer whichcontains a thermoplastic resin and has the oxygen permeability of 1000cc/(m²·24 h·atm) or more. If the oxygen permeability of the isolationlayer (A) is less than 1000 cc/(m²·24 h·atm), the rate of absorbingoxygen by the deoxidizing multilayered body of the present inventionbecomes slow, and therefore undesirable. The oxygen permeabilityindicates the value that is measured by using OX-TRAN-2/21 manufacturedby MOCON, Inc. under the conditions having the measurement temperatureof 25° C. and the cell area of 50 cm².

The representative examples of the thermoplastic resin that is used forthe isolation layer (A) include a polyolefin resin like polyethylene, anethylene-α-olefin copolymer, polypropylene, a propylene-ethylene randomcopolymer, a propylene-ethylene block copolymer, an ethylene-cyclicolefin copolymer, etc, various ion cross-linked products of anethylene-(meth)acrylate copolymer, an ethylene-methyl (meth)acrylate,and an ethylene-(meth)acrylate copolymer, an ethylenic copolymer like anethylene-vinyl acetate copolymer, etc., a synthetic rubber resin likepolybutadiene, polyisoprene, a styrene-butadiene copolymer, etc., andtheir hydrogenated resins, and a copolymer of soft polyvinyl chloride,polystyrene, polymethyl pentene, a silicone resin, and polysiloxane andother resin, etc., and they can be used singly or in combinationthereof.

The thickness of the isolation layer (A) is preferably 1 to 100 μm, andmore preferably 1 to 20 μm. In this case, the oxygen absorption rate ofthe deoxidizing multilayered body can be increased more compared to acase in which the thickness does not fall within the above range.

In the deoxidizing multilayered body of the present invention, theisolation layer (A) is preferably an acidic gas absorbent isolationlayer (Aa), which is made of an acidic gas absorbent resin composition(a) that contains an acidic gas absorbent and a thermoplastic resin. Byusing the acidic gas absorbent isolation layer (Aa) as the isolationlayer (A), the acidic gas which is produced as a by-product with theoxygen absorption reaction can be absorbed and the odor originatingtherefrom can be suppressed.

The acidic gas absorbent used for the present invention is a compoundwhich chemically and/or physically fixes odorous components mainlyoriginating from carboxylic acids. The acidic gas absorbent used for thepresent invention is preferably a base compound for the reason that itcan neutralize the odorous components originating from carboxylic acids,and therefore is effective for chemical fixing of the odorouscomponents.

Preferred examples of the base compound include an inorganic basecompound like a hydroxide, a carbonate, a hydrogen carbonate, an oxide,etc. of a metal belonging to Group 1 and Group 2 of the PeriodicalTable. Based on the reason of high basicity, a hydroxide and an oxide ofthe metal belonging to Group 2 are particularly preferable.Specifically, sodium hydroxide, potassium hydroxide, calcium hydroxide,magnesium hydroxide, sodium carbonate, potassium carbonate, calciumcarbonate, magnesium carbonate, sodium hydrogen carbonate, potassiumhydrogen carbonate, calcium hydrogen carbonate, calcium oxide ormagnesium oxide, etc. is preferable for the reason that they areexcellent in economy. Magnesium oxide is particularly preferred based onthe reason that it has high safety. In addition, it is also possible touse an organic base compound as the base compound, and therepresentative example includes an amine compound having a non-covalentelectron pair on the nitrogen.

The compounding ratio of the acidic gas absorbent is preferably 0.01 to50 parts by mass, and particularly preferably 0.1 to 10 parts by massrelative to the 100 parts by mass of the thermoplastic resin containedin the acidic gas absorbent resin composition (a). In this case, notonly the absorption capability of absorbing an acidic gas is increasedcompared to a case in which the compounding ratio does not fall withinthe above range, but also reduction in the oxygen permeability of theacidic gas absorbent isolation layer (Aa), that is caused by the acidicgas absorbent, can be prevented.

The acidic gas absorbent resin composition (a) which constitutes theacidic gas absorbent isolation layer (Aa) may be produced by, forexample, mixing a thermoplastic resin and a powdery acidic gas absorbentat the temperature which is the same or higher than the meltingtemperature of the resin.

[Oxygen Absorption Layer (B) and Odor Absorption Layer (C)]

The oxygen absorption layer (B) which constitutes the deoxidizingmultilayered body of the present invention is made of an oxygenabsorbent resin composition (b) that contains an oxidizablethermoplastic resin and a transition metal catalyst. In the deoxidizingmultilayered body of the present invention, the oxygen absorption layer(B) is essential for obtaining sufficient oxygen absorption rate.

The thickness of the oxygen absorption layer (B) is preferably 1 to 300μm, and more preferably 1 to 200 μm. In this case, the oxygen absorptionrate of the deoxidizing multilayered body can be increased more comparedto a case in which the thickness does not fall within the above range,and at the same time loss of flexibility as a packaging material can beprevented.

The oxidizable thermoplastic resin that is used for the presentinvention means a thermoplastic resin which has any one of an arylgroup, a benzyl group, an alcohol group, an ether group, an aldehydegroup, a ketone group, and a tertiary carbon. Among them, in the presentinvention, it is preferable to use a thermoplastic resin having an arylgroup as the oxidizable thermoplastic resin.

Examples of the oxidizable thermoplastic resin that is contained in theoxygen absorbent resin composition (b) include an organic polymercompound having a portion in which carbons are bonded via a double bond,an organic polymer compound having a hydrogen atom bonded to a tertiarycarbon atom, and an organic polymer compound having a benzyl group, andthey can be used singly or in combination thereof. The carbon-carbondouble bond in the organic polymer compound having a portion in whichcarbons are bonded via a double bond may be present in the main chain orthe side chain of the polymer. Representative examples include1,4-polybutadiene, 1,2-polybutadiene, 1,4-polyisoprene,3,4-polyisoprene, styrene butadiene rubber, a styrene-butadiene-styreneblock copolymer, a styrene-isoprene-styrene block copolymer, anethylene/methyl acrylate/cyclohexenyl methyl acrylate copolymer, etc.Further, examples of the organic polymer compound having a hydrogen atombonded to a tertiary carbon atom include polypropylene, polymethylpentene, etc. Examples of the organic polymer compound having a benzylgroup include hydrogenated styrene butadiene rubber, hydrogenatedstyrene isoprene rubber, etc. Among them, an organic polymer compoundhaving a portion in which carbons are bonded via a double bond ispreferable, and 1,2-polybutadiene is more preferable.

The transition metal catalyst is a catalyst which contains a metalcompound like a salt, an oxide, or the like of a transition metalelement. As the transition metal element, manganese, iron, cobalt,nickel, and copper are appropriate. Manganese, iron, and cobalt areparticularly appropriate as they exhibit an excellent catalyticactivity. Examples of the salt of the transition metal element include amineral acid salt and a fatty acid salt of the transition metal element.Examples thereof include a hydrochloric acid salt, a sulfuric acid salt,a nitric acid salt, an acetic acid salt, or a higher fatty acid salt ofthe transition metal element. Representative examples include cobaltoctylate, manganese octylate, manganese naphthenate, iron naphthenate,cobalt stearate, etc.

The transition metal catalyst that is preferable in terms ofhandleability is a supported catalyst in which salts of the transitionmetal element are supported on a carrier. Type of the carrier is notparticularly limited, however, zeolite, diatomaceous earth, calciumsilicate, etc. may be used. In particular, an aggregate having a size of0.1 to 200 μm during and after preparation of the catalyst is preferableas it has good handleability. In particular, a carrier which has a sizeof 10 to 100 nm when dispersed in a resin composition is preferable asit can give a transparent resin composition when it is compounded with aresin composition. Examples of such carrier include synthetic calciumsilicate. The compounding ratio of the transition metal catalyst to theoxygen absorbent resin composition (b) is, from the view point of theoxygen absorption capability, physical strength, and economy, preferably0.001 to 10% by mass, and particularly preferably 0.01 to 1% by mass interms of the mass of the metal atom in the oxygen absorbent resincomposition (b).

The odor absorption layer (C) which constitutes the deoxidizingmultilayered body of the present invention is made of the odor absorbentresin composition (c) that contains a thermoplastic resin and an odorabsorbent. In the deoxidizing multilayered body of the presentinvention, the odor absorption layer (C) containing an odor absorbent isessential for absorbing odor originating from aldehydes that areproduced as a by-product of an oxygen absorption reaction.

Further, it is preferable that the odor absorbent resin composition (c)is an odor absorption resin composition (cx) that contains an oxidizablethermoplastic resin, a transition metal catalyst, and an odor absorbentsince the oxygen absorption capability of the deoxidizing multilayeredbody tends to increase more. The oxidizable thermoplastic resin andtransition metal catalyst that are contained in the odor absorptionresin composition (cx) may be the same as those as exemplified beforefor the above-mentioned oxygen absorbent resin composition (b). Further,the compounding ratio of the transition metal catalyst is preferably0.001 to 10% by mass, and particularly preferably 0.01 to 1% by mass interms of the mass of the metal atom in the odor absorbent resincomposition (cx), similar to the oxygen absorbent resin composition (b).

With regard to the oxidizable thermoplastic resin that is contained inthe oxygen absorbent resin composition (b) and the odor absorbent resincomposition (cx), considering the laminate adhesion between the oxygenabsorption layer (B) and the odor absorption layer (C) it is preferableto select resins having a fusibility to each other or the identicalresin. Further, with respect to the oxidizable thermoplastic resincontained in the oxygen absorbent resin composition (b), it ispreferable to select resins having a fusibility to each otherconsidering the laminate adhesion between the oxygen absorption layer(B), and the isolation layer (A) and the odor absorption layer (C).

The thickness of the odor absorption layer (C) is preferably 1 to 300μm, and more preferably 1 to 200 μm, respectively. In this case, theoxygen absorption rate of the deoxidizing multilayered body can beincreased more compared to a case in which the thickness does not fallwithin the above range, and at the same time loss of flexibility as apackaging material can be prevented.

The odor absorbent used in the present invention is a substance whichchemically and/or physically fixes odorous components mainly originatingfrom aldehydes. With respect to the odor absorbent used in the presentinvention, any substance having the above property can be used withinthe range which does not impair the effect of the present invention.However, based on the reason that the odorous components originatingfrom aldehydes, especially acetaldehydes can be effectively fixed, amongthem, a hydrazine derivative, a urea derivative, or a guanidinederivative is preferably used as an odor absorbent. In this case, thederivative may be used singly or in combination thereof as an odorabsorbent, or they may be used as an odor absorbent by combining it withother substances. Further, a commercially available deodorant having thefunction described above may be also used as an odor absorbent.

Further, a hydrazine derivative, a urea derivative, or a guanidinederivative may be supported on a carrier and used as an odor absorbent.It is more preferable to use it in this embodiment since physicaladsorption of the aldehydes on the carrier is also expected. Type of thecarrier is not specifically limited, however, zeolite, diatomaceousearth, calcium silicate, porous silica, activated white clay, etc. maybe used. Among them, calcium silicate, porous silica, and activatedwhite clay are preferable. The amount of a hydrazine derivative, a ureaderivative, or a guanidine derivative supported on the carrier ispreferably 0.001 to 30 mmol/(g-carrier), and more preferably 0.01 to 10mmol/(g-carrier).

The compounding ratio of the odor absorbent is preferably 0.1 to 50% bymass, and particularly preferably 0.1 to 10% by mass in the odorabsorbent resin composition (c). In this case, there is an advantagethat the odor absorption capability or the transparency is better than acase in which the compounding ratio does not fall within the aboverange.

The hydrazine derivative indicates an organic substance having N—NH₂group like hydrazine, phenyl hydrazine and its derivative,semicarbazide, hydrazide and its derivative, an aminoguanidinederivative, hydrazine double salt, etc. Specifically, preferred examplesinclude hydrazine, hydrazine sulfate, hydrazine hydrochloride,monomethylhydrazine, 1,1-dimethylhydrazine, aluminum sulfate hydrazinedouble salt, carbazic acid, formohydrazide, isopropylhydrazine sulfate,tert-butylhydrazine hydrochloride, 1-aminopyrrolidine, aminoguanidinesulfate, aminoguanidine hydrochloride, aminoguanidine bicarbonate,diaminoguanidine hydrochloride, triaminoguanidine nitrate,acethydrazide, benzohydrazide, pentanohydrazide, carbohydrazide,cyclohexane carbohydrazide, benzenesulfonohydrazide, thiocarbohydrazide,thiobenzohydrazide, pentane imidehydrazide, benzohydrazonohydrazide,adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide,isophthalic acid dihydrazide, propionic acid hydrazide, salicylic acidhydrazide, 3-hydroxy-2-naphthoic acid hydrazide, oxamic acid hydrazide,oxalyldihydrazide, benzophenone hydrazone, N-aminopolyacrylamide,thiosemicarbazide, 4-methylthiosemicarbazide,4,4-dimethyl-3-thiosemicarbazide, semicarbazide hydrochloride, and4-amino-1,2,4-triazole. Among them, aluminum sulfate hydrazine doublesalt, aminoguanidine sulfate, and aminoguanidine hydrochloride areparticularly preferable.

Among the hydrazine derivatives described above, based on the reasonthat the odorous components originating from aldehydes can be moreeffectively fixed, the aminoguanidine derivative, the hydrazine doublesalt, or their mixtures are preferable.

The aminoguanidine derivative indicates the hydrazine derivative havinga guanidine structure that is represented by the following structuralformula (1) or its salt, and examples thereof include aminoguanidinesulfate, aminoguanidine hydrochloride, etc.

[Kagaku 1]

Further, R¹ to R⁴ in the formula represent any element and/or asubstituent group, and preferably a hydrogen atom, an alkyl group, or anamino group.

The hydrazine double salt indicates a double salt which is formed bychemical bond between an acidic metal salt and hydrazine. Examples ofthe metal in the acidic metal salt include magnesium, aluminum, andchrome, and examples of the salt include one kind of a sulfate, ahydrochloride, and a phosphate, or a mixture thereof. For example, whenaluminum sulfate and hydrazine are admixed with each other in water, ahydrazine double salt is produced, and it is referred to as aluminumsulfate hydrazine double salt.

Hydrazine (N₂H₄) as a chemical compound has an odor absorptioncapability. However, as it has low boiling temperature, i.e., 113° C.,and is easily decomposed, it is not easy to obtain the odor absorbentresin composition (c) of the present invention by kneading it with aresin. However, by preparing a hydrazine double salt, thesedisadvantages can be overcome while the odor absorption capability thathydrazine intrinsically possesses is maintained, and thus it is apreferred embodiment of the present invention to use an odor absorbentcontaining the hydrazine double salt.

The urea derivative indicates a compound which has the structure that isrepresented by the following structural formula (2) and does not have aN—NH₂ group in the molecule. Specific examples thereof include urea,1-methylurea, 1,1-dimethylurea, 1,3-dimethylurea, ethylurea,1,1-diethylurea, 1,3-diethylurea, arylurea, acetylurea,1-acetyl-3-methylurea, hydroxyurea, 2-hydroxyethylurea,1,3-(hydroxymethyl)urea, nitrourea, acetone semicarbazone, acetaldehydesemicarbazone, azodicarbonamide, ethyleneurea,1-acetyl-2-imidazolidinone, hydantoin, 1-arylhydantoin, glycoluryl,allantoin, biurette, biurea, thiourea, N-methylthiourea,1,3-dimethylthiourea, trimethylthiourea, 1,3-diethyl-2-thiourea,N,N′-diisopropylthiourea, 1-aryl-2-thiourea, 1-acetyl-2-thiourea,acetone thiosemicarbazone, ethylenethiourea,4,4-dimethyl-2-imidazolidine thione, guanylthiourea, 2,5-dithiobiurea,etc.

[Kagaku 2]

Further, R⁵ to R⁷ in the formula represent any element and/or anysubstituent group other than an amino group (—NH₂), and they arepreferably a hydrogen atom or an alkyl group. Further, Y represents anoxygen atom or a sulfur atom.

The guanidine derivative indicates a compound which has the guanidinestructure that is represented by the following structural formula (3)and does not have a N—NH₂ group in the molecule. Specific examplesthereof include guanidine, 1-methylguanidine hydrochloride,cyanoguanidine, 1-ethyl-3-guanidinothiourea hydrochloride, creatinine, acreatinine hydrate, 2,4-diamino-1,3,5-triazine,2,4-diamino-6-methyl-1,3,5-triazine, 2-vinyl-4,6-diamino-1,3,5-triazine,2-chloro-4,6-diamino-1,3,5-triazine,2,4-diamino-6-dimethylamino-1,3,5-triazine,2,4-diamino-6-methoxy-1,3,5-triazine,2,4-diamino-6-isopropoxy-1,3,5-triazine,2-amino-4-methoxy-6-methyl-1,3,5-triazine, ammeline, ammelide, melamine,trichloromelamine, 2-aminopyrimidine, 2,4-diaminopyrimidine,2,4,6-triaminopyrimidine, 2,4,6-triamino-5-nitrosopyrimidine,2-amino-4-methylpyrimidine, 2-amino-5-nitropyrimidine,2-amino-5-chloropyrimidine, 2-amino-5-bromopyrimidine,2-aminobenzimidazole, 2-aminopurine, 2,6-diaminopurine, guanine,6-thioguanine, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, etc.

[Kagaku 3]

Further, R⁸ to R¹¹ in the formula represent any element and/or anysubstituent group other than an amino group (—NH₂), and they arepreferably a hydrogen atom or an alkyl group.

The odor absorbent used in the present invention has a particularlysignificant effect on absorption of aldehydes.

In the oxygen absorbent resin composition (b) which constitutes theoxygen absorption layer (B) and the odor absorbent resin composition(cx) which constitutes the odor absorption layer (C), a thermoplasticresin that is different from the oxidizable thermoplastic resin may befurther compounded to improve the dispersability of other compoundingcomponents or to increase the oxygen absorption rate by enhancing theoxygen permeability of each layer described above. Examples of suchdifferent thermoplastic resin include high density polyethylene, lowdensity polyethylene, linear low density polyethylene, metallocenelinear low density polyethylene (herein below, described as “m-LLDPE”),polypropylene, an ethylene vinyl acetate copolymer, polystyrene,polymethylpentene, an ethylene vinyl alcohol copolymer, etc. Thecompounding amount of the thermoplastic resin is preferably 1000 partsby mass or less, and particularly preferably 500 parts by mass or lessrelative to 100 parts by mass of the oxidizable thermoplastic resin.When the compounding amount is 1000 parts by mass or less, thecompounding amount of the oxidizable thermoplastic resin relativelyincreases, and as a result, reduction in the oxygen absorptioncapability can be more sufficiently inhibited compared to a case inwhich the compounding amount is more than 1000 parts by mass. Further,the thermoplastic resin to be compounded preferably has high miscibilitywith oxidizable thermoplastic resin or high oxygen permeability afterformed into a film.

According to the deoxidizing multilayered body of the present invention,if desired, a photoinitiator may be included in the oxygen absorbentresin composition (b) and/or the odor absorbent resin composition (cx)to activate the oxygen absorption reaction. The photoinitiator is asubstance which has a function to effectively generate active species ina reaction system of the oxygen absorption reaction by light irradiationand increase the reaction speed. In the present invention, it ispreferable that the photoinitiator molecule which is excited by lightirradiation extracts a hydrogen from the oxidizable thermoplastic resinto give an active radical, and thus initiates the oxidation reaction.

Representative examples of the photoinitiator include benzophenone andits derivative, a thiazine dye, a metal porphyrin derivative, ananthraquinone derivative, etc. Preferred is a benzophenone derivativewhich contains a benzophenone skeleton structure. The compounding ratioof the photoinitiator is preferably 0.001 to 10% by mass, andparticularly preferably 0.01 to 1% by mass in each of the resincompositions.

The light irradiated to the deoxidizing multilayered body of the presentinvention is one kind of electromagnetic wave which gives an energy tothe photoinitiator to have it in the exited state. The wavelength of thelight for activating the oxygen absorption is preferably 180 nm to 800nm, and UV light in the range of 200 to 380 nm is particularlypreferable.

The photoinitiator may be included in both the oxygen absorbent resincomposition (b) and the odor absorbent resin composition (cx). However,as the active species that are generated by light irradiation are moreeasily produced from the oxygen absorbent resin composition (b) and theactive species are transferred to the odor absorbent resin composition(cx), it can be included only in the oxygen absorbent resin composition(b), and this embodiment is economical and desirable.

As a method of activating the oxygen absorption other than thosedescribed above, the oxidation reaction can be initiated by extracting ahydrogen from the oxidizable thermoplastic resin by applying an energyfrom outside like a radioation such as electromagnetic ray, α ray, βray, γ ray, X ray, etc., and heat, high frequency wave, ultrasonic wave,etc., and by providing it as a radical.

By including at least one additive selected from a drying agent, anadsorbent, an anti-bacterial agent, and a coloring agent to the oxygenabsorbent resin composition (b) which constitutes the oxygen absorptionlayer (B) and/or the odor absorbent resin composition (c) whichconstitutes the odor absorption layer (C) of the present invention, thecomposition described above can be prepared into a composition which hasan oxygen absorption function and also other functions like dryingfunction, etc. Further, the deoxidizing multilayered body of the presentinvention can be prepared into a multilayered body which contains atleast one additive selected from a drying agent, an adsorbent, ananti-bacterial agent, and a coloring agent within the range which doesnot impair the effect of the present invention.

The drying agent means an agent which absorbs moisture from the air, andexamples thereof include silica gel, quicklime, calcium chloride,phosphorus pentoxide, aluminum oxide, etc.

The adsorbent means an agent which physically fixes an atom, a molecule,a particulate, etc. on its surface, and specific examples thereofinclude active carbon, zeolite, silica gel, aluminum oxide, etc. Amongthem, silica gel and aluminum oxide are preferable because they alsohave a function of a drying agent.

The anti-bacterial agent means an agent which inhibits growth ofbacteria or kills bacteria, and specific examples thereof include aninorganic anti-bacterial agent or an organic anti-bacterial agent. Inaddition, the examples of the inorganic anti-bacterial agent includesilver, copper, zinc, or their chemical compounds, and the examples ofthe organic anti-bacterial agent include hinokitiol and chitosan inaddition to a chemical like a quaternary ammonium salt, thiabendazole,organic silicone quaternary ammonium salt, etc. The naturalanti-bacterial agent is more preferable from the viewpoint of safety.

The coloring agent means an agent which is used for coloring whole or apart of the deoxidizing multilayered body of the present invention, andexamples thereof include an inorganic pigment like titanium oxide and anorganic pigment like phthalocyanine, etc.

The compounding ratio of the inorganic base and the amine compound inthe oxygen absorbent resin composition (b) which constitutes the oxygenabsorption layer (B) used in the present invention is preferably 1% bymass or less, and particularly preferably less than 0.1% by mass. Inthis case, the oxygen absorption capability of the deoxidizingmultilayered body can be improved more compared to a case in which theinorganic base and/or the amine compound are contained in an amount ofmore than 1% by mass in the oxygen absorption layer (B).

The inorganic base mentioned in the present invention means an inorganiccompound which exhibits a basic property, and the oxidizablethermoplastic resin, the transition metal catalyst, and thephotoinitiator are not included therein. As the inorganic base inhibitsthe oxidation reaction of the oxidizable thermoplastic resin, the oxygenabsorption capability of the deoxidizing multilayered body issignificantly decreased if the inorganic base is included in the oxygenabsorption layer (B).

Examples of the inorganic base include a hydroxide, a carbonate, ahydrogen carbonate, an oxide, etc. of a metal belonging to Group 1 andGroup 2 of the Periodical Table. Specific examples thereof includelithium hydroxide, sodium hydroxide, potassium hydroxide, rubidiumhydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide,barium hydroxide, magnesium hydroxide, sodium carbonate, potassiumcarbonate, calcium carbonate, magnesium carbonate, sodium hydrogencarbonate, potassium hydrogen carbonate, calcium hydrogen carbonate,calcium oxide, magnesium oxide, etc. Among them, lithium hydroxide,sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesiumhydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide,magnesium hydroxide, calcium oxide, and magnesium oxide significantlyinhibit the oxidation of the oxidizable thermoplastic resin.

The amine compound mentioned in the present invention means a compoundwhich contains a primary to a tertiary or a quaternary ammonium ion inthe molecule, and the oxidizable thermoplastic resin, the transitionmetal catalyst, and the photoinitiator are not included therein. As theamine compound inhibits the oxidation reaction of the oxidizablethermoplastic resin, the oxygen absorption capability of the deoxidizingmultilayered body is significantly decreased if the amine compound isincluded in the oxygen absorption layer (B).

Examples of the amine compound include an aliphatic amine, an aromaticamine, a hydroxide of tetraallkylammonium, a hydrazine derivative, aurea derivative, a guanidine derivative, etc. Examples of the aliphaticamine include methylamine, ethylamine, dimethylamine, diethylamine,trimethylamine, triethylamine, ether amine, triethanolamine,N,N-diisopropylethylamine, piperidine, piperazine, morpholine,quinuclidine, amantadine, an amino acid, etc.

Examples of the aromatic amine include pyridine,4-dimethylaminopyridine, aniline, toluidine, benzidine, triethylamine,ethylenediamine, tetramethylethylenediamine, hexamethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,pentaethylenehexamine, spermidine, spermine, diazabicycloundecene,aniline, catechol amine, phenethylamine,1,8-bis(dimethylamino)naphthalene, etc. Examples of the hydroxide oftetraalkylammonium include tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc.

The hydrazine derivative indicates an organic substance having N—NH₂group like hydrazine, phenyl hydrazine and its derivative,semicarbazide, hydrazide and its derivative, an aminoguanidinederivative, hydrazine double salt, etc. Specific examples includehydrazine, hydrazine sulfate, hydrazine hydrochloride,monomethylhydrazine, 1,1-dimethylhydrazine, aluminum sulfate hydrazinedouble salt, carbazic acid, formohydrazide, isopropylhydrazine sulfate,tert-butylhydrazine hydrochloride, 1-aminopyrrolidine, aminoguanidinesulfate, aminoguanidine hydrochloride, aminoguanidine bicarbonate,diaminoguanidine hydrochloride, triaminoguanidine nitrate,acethydrazide, benzohydrazide, pentanohydrazide, carbohydrazide,cyclohexane carbohydrazide, benzenesulfonohydrazide, thiocarbohydrazide,thiobenzohydrazide, pentane imidehydrazide, benzohydrazonohydrazide,adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide,isophthalic acid dihydrazide, propionic acid hydrazide, salicylic acidhydrazide, 3-hydroxy-2-naphthoic acid hydrazide, oxamic acid hydrazide,oxalyldihydrazide, benzophenone hydrazone, N-aminopolyacrylamide,thiosemicarbazide, 4-methylthiosemicarbazide,4,4-dimethyl-3-thiosemicarbazide, semicarbazide hydrochloride,4-amino-1,2,4-triazole, etc.

The aminoguanidine derivative indicates the hydrazine derivative havinga guanidine structure that is represented by the following structuralformula (1) or its salt, and examples thereof include aminoguanidinesulfate, aminoguanidine hydrochloride, etc.

[Kagaku 4]

Further, R¹ to R⁴ in the formula represent any element and/or asubstituent group, and preferably a hydrogen atom, an alkyl group, or anamino group.

The hydrazine double salt indicates a double salt which is formed bychemical bond between an acidic metal salt and hydrazine. Examples ofthe metal in the acidic metal salt include magnesium, aluminum, andchrome, and examples of the salt include any one kind of a sulfate, ahydrochloride, and a phosphate, or a mixture thereof. For example, whenaluminum sulfate and hydrazine are admixed with each other in water, ahydrazine double salt is produced, and it is referred to as aluminumsulfate hydrazine double salt.

The urea derivative indicates a compound which has the structure that isrepresented by the following structural formula (2) and does not have aN—NH₂ group in the molecule. Specific examples thereof include urea,1-methylurea, 1,1-dimethylurea, 1,3-dimethylurea, ethylurea,1,1-diethylurea, 1,3-diethylurea, arylurea, acetylurea,1-acetyl-3-methylurea, hydroxyurea, 2-hydroxyethylurea,1,3-(hydroxymethyl)urea, nitrourea, acetone semicarbazone, acetaldehydesemicarbazone, azodicarbonamide, ethyleneurea,1-acetyl-2-imidazolidinone, hydantoin, 1-arylhydantoin, glycoluryl,allantoin, biurette, biurea, thiourea, N-methylthiourea,1,3-dimethylthiourea, trimethylthiourea, 1,3-diethyl-2-thiourea,N,N′-diisopropylthiourea, 1-aryl-2-thiourea, 1-acetyl-2-thiourea,acetone thiosemicarbazone, ethylenethiourea,4,4-dimethyl-2-imidazolidine thione, guanylthiourea, 2,5-dithiobiurea,etc.

[Kagaku 5]

Further, R⁵ to R⁷ in the formula represent any element and/or anysubstituent group other than an amino group (—NH₂), and they arepreferably a hydrogen atom or an alkyl group.

Further, Y represents an oxygen atom or a sulfur atom.

The guanidine derivative indicates a compound which has the guanidinestructure that is represented by the following structural formula (3)and does not have a N—NH₂ group in the molecule. Specific examplesthereof include guanidine, 1-methylguanidine hydrochloride,cyanoguanidine, 1-ethyl-3-guanidinothiourea hydrochloride, creatinine,creatinine hydrate, 2,4-diamino-1,3,5-triazine,2,4-diamino-6-methyl-1,3,5-triazine, 2-vinyl-4,6-diamino-1,3,5-triazine,2-chloro-4,6-diamino-1,3,5-triazine,2,4-diamino-6-dimethylamino-1,3,5-triazine,2,4-diamino-6-methoxy-1,3,5-triazine,2,4-diamino-6-isopropoxy-1,3,5-triazine,2-amino-4-methoxy-6-methyl-1,3,5-triazine, ammeline, ammelide, melamine,trichloromelamine, 2-aminopyrimidine, 2,4-diaminopyrimidine,2,4,6-triaminopyrimidine, 2,4,6-triamino-5-nitrosopyrimidine,2-amino-4-methylpyrimidine, 2-amino-5-nitropyrimidine,2-amino-5-chloropyrimidine, 2-amino-5-bromopyrimidine,2-aminobenzimidazole, 2-aminopurine, 2,6-diaminopurine, guanine,6-thioguanine, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, etc.

[Kagaku 6]

Further, R⁸ to R¹¹ in the formula represent any element and/or anysubstituent group other than an amino group (—NH₂), and they arepreferably a hydrogen atom or an alkyl group.

Among these amine compounds, in particular, ethylenediamine,tetramethylethylenediamine, hexamethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,diazabicycloundecene, tetramethylammonium hydroxide, tetraethylammoniumhydroxide, hydrazine, hydrazine sulfate, hydrazine hydrochloride,aluminum sulfate hydrazine double salt, carbazic acid, formohydrazide,1,5-diphenylcarbonohydrazide, isopropylhydrazine sulfate,tert-butylhydrazine hydrochloride, aminoguanidine sulfate,aminoguanidine hydrochloride, aminoguanidine bicarbonate,diaminoguanidine hydrochloride, triaminoguanidine nitrate, urea,thiourea, ethyleneurea, melamine, adipic acid dihydrazide, and sebacicacid dihydrazide significantly inhibit the oxidation of the oxidizablethermoplastic resin.

The total compounding ratio of the inorganic base and the amine compoundin the oxygen absorbent resin composition (b) which constitutes theoxygen absorption layer (B) is most preferably 0% by mass. In this case,the inorganic base and the amine compound are not included in the oxygenabsorption layer (B), and therefore the oxygen absorption capability ofthe deoxidizing multilayered body can be improved more compared to acase in which the inorganic base and/or the amine compound are includedin the oxygen absorbent resin composition (b).

Herein, the total compounding ratio of 0% by mass for the inorganic baseand the amine compound in the oxygen absorbent resin composition (b)means that the oxygen absorbent resin composition (b) has theconstitution as follows.

Namely, it means that the total compounding ratio of the oxidizablethermoplastic resin, the transition metal catalyst, and accessorycomponents in the oxygen absorbent resin composition (b) is 100% by masswhen the oxygen absorbent resin composition (b) contains an oxidizablethermoplastic resin, a transition metal catalyst, and accessorycomponents.

Herein, the accessory components indicate at least one component that isselected from the group consisting of a photoinitiator, a thermoplasticresin which is different from the oxidizable thermoplastic resin, andadditives. In addition, the accessory components are different from theinorganic base and the amine compound which are described above.

The oxygen absorbent resin composition (b) which constitutes the oxygenabsorption layer (B) can be produced, for example, by mixing a resincomposition containing an oxidizable thermoplastic resin with a resincomposition containing a transition metal catalyst at the temperaturewhich is the same or higher than the melting temperature of the resin.

The odor absorbent resin composition (c) which constitutes the odorabsorption layer (C) can be produced, for example, by mixing a resincomposition containing a thermoplastic resin with a resin compositioncontaining an odor absorbent at the temperature which is the same orhigher than the temperature at which each resin composition melts.Alternatively, it can be produced by mixing a resin compositioncontaining a thermoplastic resin with a powdery odor absorbent at thetemperature which is the same or higher than the melting temperature ofthe resin composition.

The odor absorbent resin composition (cx) which constitutes the odorabsorption layer (C) can be produced, for example, by mixing a resincomposition containing an oxidizable thermoplastic resin with a resincomposition containing a transition metal catalyst and a resincomposition containing an odor absorbent at the temperature which is thesame or higher than the temperature at which each resin compositionmelts. Alternatively, it can be produced by mixing a resin compositioncontaining an oxidizable thermoplastic resin with a resin compositioncontaining a transition metal catalyst and a powdery odor absorbent atthe temperature which is the same or higher than the temperature atwhich each resin composition melts. Further, it can be also produced bymixing a resin composition containing an oxidizable thermoplastic resinand a transition metal catalyst with a powdery odor absorbent at thetemperature which is the same or higher than the melting temperature ofthe resin composition.

[Oxygen Barrier Layer (D)]

The oxygen barrier substance which constitutes the oxygen barrier layer(D) means a substance having the oxygen permeability of 100 cc/(m²·24h·atm) or less. Representative examples of the oxygen barrier layer (D)include a metal foil like an aluminum foil, in addition to a layercontaining polyester, polyamide, nylon MXD6, an ethylene-vinyl alcoholcopolymer, a vinylidene chloride, etc. to which silica or alumina isvapor-deposited. The thickness of the oxygen barrier layer (D) ispreferably 1 to 300 μm, and more preferably 1 to 100 μm. In this case,the oxygen barrier effect can be improved more and loss of flexibilityas a packaging material can be simultaneously prevented compared to acase in which the thickness does not fall within the above range.

The deoxidizing multilayered body of the present invention can beproduced, for example, by co-extrusion of a multilayered body having amultilayer structure in which the isolation layer (A), the oxygenabsorption layer (B), the odor absorption layer (C), and the oxygenbarrier layer (D) are laminated in this order, by using a machine forproducing a multilayered film. Or, it is also possible that amultilayered body having a multilayer structure in which the isolationlayer (A), the oxygen absorption layer (B), and the odor absorptionlayer (C) are laminated in this order is produced by co-extrusion byusing a machine for producing a multilayered film, and then the oxygenbarrier layer (D) is laminated thereto by using an adhesive. Further,for the co-extrusion, an adhesive resin may be used for each interlayerregion if necessary. Further, in addition to the each layer describedabove, an optional layer may be laminated within the range that acertain property of the deoxidizing multilayered body of the presentinvention is not impaired, and the layers may be laminated by combiningvarious methods.

The deoxidizing multilayered body of the present invention may be usedas a deoxidizing packaging material on a part or whole of a packagingcontainer like a packaging bag, etc. FIG. 2 is a cross-sectional view ofan embodiment of a deoxidizing packaging container according to thepresent invention, illustrating an example of using the deoxidizingmultilayered body 10 of FIG. 1. As shown in FIG. 2, a deoxidizingpackaging container 100 has two deoxidizing multilayered bodies 10. Bothof the deoxidizing multilayered bodies 10 are bonded to be in a state inwhich the isolation layer (A) faces the inside. The deoxidizingpackaging container 100 may be produced, for example, by heat-sealingthe edge parts of the deoxidizing multilayered bodies 10. Further, whileFIG. 2 illustrates an example in which the deoxidizing multilayered bodyis used on whole of a packaging container, it can be used on a part of apackaging container by using it as a cover material of a container or onjust one surface of a pouch bag.

Further, the deoxidizing multilayered body of the present invention maybe used as a deoxygenizer that is processed into a sheet shape or a filmshape, or used as a deoxidizer packaging body having a shape in whichthe processed deoxidizer is enclosed in an air-permeable sachet.Further, it can be used as a deoxygenizer after molding into a shapelike a label, a card, a packing, etc.

As for the oxygen absorbent resin composition (b) which constitutes theoxygen absorption layer (B) and the odor absorbent resin compositions(c) and (cx) which constitute the odor absorption layer (C), byselecting a resin with high transparency and finely dispersing anadditive like a catalyst, an odor absorbent, etc. in the resincomposition, the transparent compositions can be obtained. Thus, byusing a transparent resin for each layer like the isolation layer (A),the odor absorption layer (C), the oxygen barrier layer (D), etc. whichconstitute the multilayered film, a transparent deoxidizing laminatesheet or film can be prepared. This transparent deoxidizing laminatesheet or film is appropriate for a packaging material having see-throughproperty.

Use of the deoxidizing multilayered body of the present invention is notlimited, and it exhibits a practically valuable deoxidizing absorptioncapability in the field of preservation and quality maintenance of foodproducts, beverages, pharmaceuticals, medical products, cosmetics, metalproducts, electronic products, etc.

In particular, since the oxygen absorption multilayered body of thepresent invention can absorb oxygen regardless of the presence orabsence of moisture in a subject to be preserved, it can be particularlypreferably used for dried food products like powder seasoning, powdercoffee, coffee bean, rice, tea, bean, Japanese rice cracker, ricecracker, etc., pharmaceuticals, health products like a vitaminpreparation, etc., and industrial materials like electronic parts, etc.

EXAMPLES

Herein below, the present invention will be described in greater detailusing the Examples and Comparative examples, but the present inventionis not limited by them. Further, in the following Examples andComparative examples, the oxygen absorption capability and odorousorganic substance release concentration were evaluated for thedeoxidizing multilayered film based on the evaluation method describedbelow.

(Method 1 for Evaluating the Deoxidizing Multilayered Film)

The deoxidizing multilayered film was illuminated with UV light from thelight source of 1 kW high pressure mercury lamp with the illuminance of6.2 mW/cm² for 90 seconds (illumination amount of 560 mJ/cm²). Afterthat, the film was processed into a bag which has an oxygen absorptionsurface area of 250 cm², to which 120 mL of a mixture gas containing 5vol % of oxygen and 95 vol % of nitrogen was added followed by sealing(initial oxygen amount: 0.024 mL/cm²). By maintaining the bag under thecondition of 25° C. and 60% RH, the period of time required for theoxygen concentration to reach 0.1 vol % was measured. Herein below, theperiod of time required for the oxygen concentration in a bag to bereduced to 0.1 vol % is referred to as deoxygenation time. Further,concentration of aldehydes and carboxylic acids in the bag afterdeoxygenation was measured by a gas detector tube for acetaldehyde(ACETALDEHYDE 92L (for low concentration), manufactured by GastecCorporation) and a gas detector tube for acetic acid (ACETIC ACID 81L,manufactured by Gastec Corporation), and the odorous organic substancerelease concentration was evaluated.

(Method 2 for Evaluating the Deoxidizing Multilayered Film)

The deoxidizing multilayered film was illuminated with UV light from thelight source of 1 kW high pressure mercury lamp with the illuminance of6.2 mW/cm² for 90 seconds (illumination amount of 560 mJ/cm²). Afterthat, the film was processed into a bag which has an oxygen absorptionsurface area of 250 cm², to which 120 mL of air was added followed bysealing (initial oxygen amount: 0.10 mL/cm²). By maintaining the bagunder the condition of 25° C. and 60% RH, the deoxygenation time wasmeasured. Further, concentration of aldehydes and carboxylic acids inthe bag after deoxygenation was measured by a gas detector tube foracetaldehyde (ACETALDEHYDE 92L (for low concentration), manufactured byGastec Corporation) and a gas detector tube for acetic acid (ACETIC ACID81L, manufactured by Gastec Corporation), and the odorous organicsubstance release concentration was evaluated.

In the following Examples and Comparative examples, a deoxidizingmultilayered film was produced by using the following transition metalcatalyst powder, odor absorbent, and various resin compositions asfollows.

(Acidic Gas Absorbent Resin Composition 1)

By melt-kneading m-LLDPE (trade name: KERNEL KC570S, manufactured byJapan Polyethylene Corporation) and magnesium oxide at mass ratio of100:1.4 by using a biaxial kneading extruder at 160° C., an acidic gasabsorbent resin composition 1 was produced.

(Transition Metal Catalyst Powder 1)

By impregnating cobalt octylate (trade name: NIKKA OCTHIX Cobalt,manufactured by Nihon Kagaku Sangyo Co., Ltd., cobalt content: 8% bymass) in synthetic calcium silicate (trade name: MICROCELL E,manufactured by Celite Corporation) followed by drying under reducedpressure, a transition metal catalyst-containing powder 1 was obtained.

(Oxygen Absorbent Resin Composition 1)

The transition metal catalyst-containing powder 1 and4-phenylbenzophenone (herein below, described as “PBP”) as aphotoinitiator were admixed with each other, and melt-kneaded withsyndiotactic 1,2-polybutadiene (trade name: RB820, manufactured by JSRCorporation, herein below, described as “RB”), which is an oxidizablethermoplastic resin, by using a biaxial kneading extruder at 140° C. toprepare an oxygen absorbent resin composition 1 (containing 0.12 partsby mass of cobalt atom, 0.75 parts by mass of synthetic calcium silicate(average particle diameter: 2 μm), and 0.21 parts by mass of PBPrelative to 100 parts by mass of RB).

(Odor Absorbent 1)

An aqueous solution of ethylene urea was impregnated in activated whiteclay (trade name: GALLEON EARTH, manufactured by Mizusawa industrialChemicals, Ltd.; herein below, descried as GE) followed by drying toobtain an odor absorbent 1 (impregnation amount of ethylene urea: 1.5mmol/(g-carrier)).

(Odor Absorbent 2)

An aqueous solution of aminoguanidine sulfate was impregnated in GEfollowed by drying to obtain an odor absorbent 2 (impregnation amount ofaminoguanidine sulfate: 0.8 mmol/(g-carrier)).

(Odor Absorbent Resin Composition 1)

m-LLDPE and an aldehyde deodorant (trade name: KESMON NS-241,manufactured by Toagosei, Co., Ltd., herein below, described as“NS-241”) were admixed with each other at mass ratio of 100:6, andmelt-kneaded by using a biaxial kneading extruder at 140° C. to preparean odor absorbent resin composition 1.

(Odor Absorbent Resin Composition 2)

The odor absorbent 1 and m-LLDPE were admixed with each other at massratio of 6:100 (ethylene urea 0.08 mmol/g), and melt-kneaded by using abiaxial kneading extruder at 140° C. to prepare an odor absorbent resincomposition 2 (containing 6 parts by mass of the odor absorbent 1relative to 100 parts by mass of m-LLDPE).

(Odor Absorbent Resin Composition 3)

The odor absorbent 2 and m-LLDPE were admixed with each other at massratio of 6:100 (aminoguanidine sulfate 0.04 mmol/g), and melt-kneaded byusing a biaxial kneading extruder at 140° C. to prepare an odorabsorbent resin composition 3 (containing 6 parts by mass of the odorabsorbent 2 relative to 100 parts by mass of m-LLDPE).

(Odor Absorbent Resin Composition 4)

The transition metal catalyst-containing powder 1 and NS-241 wereadmixed with each other, and melt-kneaded with RB by using a biaxialkneading extruder at 140° C. to prepare an odor absorbent resincomposition 4 (containing 0.13 parts by mass of cobalt atom and 6 partsby mass of NS-241 relative to 100 parts by mass of RB).

(Odor Absorbent Resin Composition 5)

The transition metal catalyst-containing powder 1, PBP, and the odorabsorbent 2 were admixed with one another, and melt-kneaded with RB byusing a biaxial kneading extruder at 140° C. to prepare an odorabsorbent resin composition 5 (containing 0.13 parts by mass of cobaltatom, 0.75 parts by mass of synthetic calcium silicate (average particlediameter: 2 μm), 0.21 parts by mass of PBP, and 6 parts by mass of theodor absorbent 2 relative to 100 parts by mass of RB).

(Odor Absorbent Resin Composition 6)

The transition metal catalyst-containing powder 1 and the odor absorbent2 were admixed with each other, and melt-kneaded with RB by using abiaxial kneading extruder at 140° C. to prepare an odor absorbent resincomposition 6 (containing 0.13 parts by mass of cobalt atom and 6 partsby mass of the odor absorbent 2 relative to 100 parts by mass of RB).

(Odor Absorbent Resin Composition 7)

The transition metal catalyst-containing powder 1, PBP, and NS-241 wereadmixed with one another, and melt-kneaded with RB by using a biaxialkneading extruder at 140° C. to prepare an odor absorbent resincomposition 7 (containing 0.13 parts by mass of cobalt atom, 0.75 partsby mass of synthetic calcium silicate (average particle diameter: 2 μm),0.21 parts by mass of PBP, and 6 parts by mass of NS-241 relative to 100parts by mass of RB).

Example 1

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 1 as the odor absorption layer (C1) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer (C1)with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (C1) side of the multilayered film produced, the oxygenbarrier layer (D) with a thickness of 12 μm, which is made of silicavapor-deposited polyethylene terephthalate (trade name: TECH BARRIER P2,manufactured by Mitsubishi Plastics, Inc., herein below, described as“SiPET”), was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film1.

The oxygen absorption capability of the deoxidizing multilayered film 1was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 15 hours,concentration of the aldehydes was 1 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 2

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 2 as the odor absorption layer (C2) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer (C2)with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (C2) side of the multilayered film produced, the oxygenbarrier layer (D) with a thickness of 12 μm, which is made of SiPET, wasbonded by dry lamination with the silica-deposited surface employed asthe adhesive surface to give a deoxidizing multilayered film 2.

The oxygen absorption capability of the deoxidizing multilayered film 2was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film”, and as a result, deoxygenation time was 16 hours,concentration of the aldehydes was 4 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 3

A multilayered film having m-LLDPE as the isolation layer (A), theoxygen absorbent resin composition 1 as the oxygen absorption layer(B1), and the odor absorbent resin composition 3 as the odor absorptionlayer (C3) was produced by laminating them in this order by co-extrusion(co-extrusion temperature was 160° C.). The layer constitution includesthe isolation layer (A) with a thickness of about 10 μm, the oxygenabsorption layer (B1) with a thickness of about 20 μm, and the odorabsorption layer (C3) with a thickness of about 20 μm, in this order.Next, to the odor absorption layer (C3) side of the multilayered filmproduced, the oxygen barrier layer (D) with a thickness of 12 μm, whichis made of SiPET, was bonded by dry lamination with the silica-depositedsurface employed as the adhesive surface to give a deoxidizingmultilayered film 3.

The oxygen absorption capability of the deoxidizing multilayered film 3was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 15 hours,concentration of the aldehydes was 1 ppm, and concentration of thecarboxylic acids was 0.7 ppm, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 4

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 4 as the odor absorption layer (Cx4) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx4) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx4) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film4.

The oxygen absorption capability of the deoxidizing multilayered film 4was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 14 hours,concentration of the aldehydes was 2 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 5

A multilayered film having m-LLDPE as the isolation layer (A), theoxygen absorbent resin composition 1 as the oxygen absorption layer(B1), and the odor absorbent resin composition 5 as the odor absorptionlayer (Cx5) was produced by laminating them in this order byco-extrusion (co-extrusion temperature was 160° C.). The layerconstitution includes the isolation layer (A) with a thickness of about10 μm, the oxygen absorption layer (B1) with a thickness of about 20 μm,and the odor absorption layer (Cx5) with a thickness of about 20 μm, inthis order. Next, to the odor absorption layer (Cx5) side of themultilayered film produced, the oxygen barrier layer (D) with athickness of 12 μm, which is made of SiPET, was bonded by dry laminationwith the silica-deposited surface employed as the adhesive surface togive a deoxidizing multilayered film 5.

The oxygen absorption capability of the deoxidizing multilayered film 5was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 16 hours,concentration of the aldehydes was 2 ppm, and concentration of thecarboxylic acids was 0.5 ppm, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 6

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 5 as the odor absorption layer (Cx5) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx5) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx5) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film6.

The oxygen absorption capability of the deoxidizing multilayered film 6was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 14 hours,concentration of the aldehydes was 1 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Example 7

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 6 as the odor absorption layer (Cx6) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx6) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx6) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film7.

The oxygen absorption capability of the deoxidizing multilayered film 7was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 14 hours,concentration of the aldehydes was 2 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Comparative Example 1

A deoxidizing multilayered film was produced in the same manner asExample 3 except that the lamination order of the oxygen absorptionlayer (B1) and the odor absorption layer (C3) was reversed to give adeoxidizing multilayered film 8.

The oxygen absorption capability of the deoxidizing multilayered film 8was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 38 hours,concentration of the aldehydes was 1 ppm, and concentration of thecarboxylic acids was 0.3 ppm, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

Comparative Example 2

A multilayered film having the isolation layer (A), the oxygenabsorption layer (B1), and the oxygen absorption layer (B1) was producedin the same manner as Example 5 except that the oxygen absorption layer(B1) made from the oxygen absorbent resin composition 1 was laminatedinstead the odor absorption layer (Cx5) made from the odor absorbentresin composition 5. To the oxygen absorption layer (B1) side of themultilayered film produced, the oxygen barrier layer (D) with athickness of 12 μm, which is made of SiPET, was bonded by dry laminationwith the silica-deposited surface employed as the adhesive surface togive a deoxidizing multilayered film 9.

The oxygen absorption capability of the deoxidizing multilayered film 9was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 14 hours,concentration of the aldehydes was 47 ppm, and concentration of thecarboxylic acids was 0.8 ppm, and strong odor was identified. Theresults are shown in Table 1. Further, when the concentration of thealdehydes was measured, a gas detector tube for acetaldehyde(ACETALDEHYDE 92M (for medium concentration), manufactured by GastecCorporation) was used.

Comparative Example 3

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the odor absorbentresin composition 7 as the odor absorption layer (Cx7), and the odorabsorbent resin composition 7 as the odor absorption layer (Cx7) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the odor absorption layer(Cx7) with a thickness of about 20 μm, and the odor absorption layer(Cx7) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx7) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film10.

The oxygen absorption capability of the deoxidizing multilayered film 10was evaluated according to the “method 1 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 62 hours,concentration of the aldehydes was 1 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 1.

TABLE 1 Evaluation results according to the “method 1 for evaluating thedeoxidizing multilayered film” Concentration of Concentration ofDeoxygenation aldehydes carboxylic acids Layer constitution time*⁾ (h)(ppm) (ppm) Example 1 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 15 1 <0.25 Odor absorption layer (C1)/Barrierlayer (D) Example 2 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 16 4 <0.25 Odor absorption layer (C2)/Barrierlayer (D) Example 3 Isolation layer (A)/Oxygen absorption layer (B1)/ 151 0.7 Odor absorption layer (C3)/Barrier layer (D) Example 4 Acidic gasabsorbent isolation layer (Aa)/Oxygen absorption layer (B1)/ 14 2 <0.25Odor absorption layer (Cx4)/Barrier layer (D) Example 5 Isolation layer(A)/Oxygen absorption layer (B1)/ 16 2 0.5 Odor absorption layer(Cx5)/Barrier layer (D) Example 6 Acidic gas absorbent isolation layer(Aa)/Oxygen absorption layer (B1)/ 14 1 <0.25 Odor absorption layer(Cx5)/Barrier layer (D) Example 7 Acidic gas absorbent isolation layer(Aa)/Oxygen absorption layer (B1)/ 14 2 <0.25 Odor absorption layer(Cx6)/Barrier layer (D) Comparative Isolation layer (A)/Odor absorptionlayer (C3)/ 38 1 0.3 example 1 Oxygen absorption layer (B1)/Barrierlayer (D) Comparative Isolation layer (A)/Oxygen absorption layer (B1)/14 47 0.8 example 2 Oxygen absorption layer (B1)/Barrier layer (D)Comparative Acidic gas absorbent isolation layer (Aa)/Odor absorptionlayer (Cx7)/ 62 1 <0.25 example 3 Odor absorption layer (Cx7)/Barrierlayer (D) *⁾Initial oxygen amount: 0.024 mL/cm²

As is clearly from Table 1, although production of odor can besuppressed in Comparative example 1 in which the odor absorption layer(C3) only having an odor absorption capability is laminated next to theisolation layer (A) by reversing the only lamination order of the oxygenabsorption layer and the odor absorption layer compared to Example 3,the result shows that the oxygen absorption rate is significantlydecreased compared to Example 3 in which the odor absorption layer islaminated next to the barrier layer (D). Namely, in Comparative example1, the problem relating to obtaining practically sufficient oxygenabsorption rate while suppressing the production of odor cannot besolved. Further, in Comparative example 2 in which the deoxidizingmultilayered body that has not been laminated with the odor absorptionlayer (C1) containing an odor absorbent is used, deoxygenated state wasreached within 14 hours after starting the test. However, theconcentration of the aldehydes in the bag reached up to 47 ppm andstrong odor was produced. Meanwhile, in Comparative example 3 in whichonly the odor absorption layer (Cx7) containing an oxidizablethermoplastic resin was laminated and the oxygen absorption layer (B1)was not laminated, the oxygen absorption capability was significantlydecreased and the deoxygenated state was just achieved after 62 hoursfrom the start of the test.

On the contrary, in Examples 1 to 3 in which the oxygen absorption layer(B1) and the odor absorption layer (C1, C2, or C3) are laminated orExample 4 to 7 in which the oxygen absorption layer (B1) and the odorabsorption layer (Cx4, Cx5, or Cx6) containing the oxidizablethermoplastic resin are laminated, the maintaining of the oxygenabsorption capability and the suppressing of the concentration of thealdehydes become compatible with each other. Further, according toExamples 1, 2, 4, 6, and 7 in which the acidic gas absorbent isolationlayer (Aa) is laminated instead of the isolation layer (A), themaintaining of the oxygen absorption capability and the suppressing ofthe concentration of the carboxylic acids and the concentration of thealdehydes become compatible with each other.

Example 8

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 1 as the odor absorption layer (C1) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer (C1)with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (C1) side of the multilayered film produced, the oxygenbarrier layer (D) with a thickness of 12 μm, which is made of SiPET, wasbonded by dry lamination with the silica-deposited surface employed asthe adhesive surface to give a deoxidizing multilayered film 11.

The oxygen absorption capability of the deoxidizing multilayered film 11was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 51 hours,concentration of the aldehydes was 8 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 2.

Example 9

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 2 as the odor absorption layer (C2) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer (C2)with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (C2) side of the multilayered film produced, the oxygenbarrier layer (D) with a thickness of 12 μm, which is made of SiPET, wasbonded by dry lamination with the silica-deposited surface employed asthe adhesive surface to give a deoxidizing multilayered film 12.

The oxygen absorption capability of the deoxidizing multilayered film 12was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 55 hours,concentration of the aldehydes was 10 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 2.

Example 10

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 4 as the odor absorption layer (Cx4) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx4) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx4) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film13.

The oxygen absorption capability of the deoxidizing multilayered film 13was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 34 hours,concentration of the aldehydes was 10 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 2.

Example 11

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 5 as the odor absorption layer (Cx5) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx5) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx5) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film14.

The oxygen absorption capability of the deoxidizing multilayered film 14was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 40 hours,concentration of the aldehydes was 10 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 2.

Example 12

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the oxygen absorbentresin composition 1 as the oxygen absorption layer (B1), and the odorabsorbent resin composition 6 as the odor absorption layer (Cx6) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the oxygen absorption layer(B1) with a thickness of about 20 μm, and the odor absorption layer(Cx6) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx6) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film15.

The oxygen absorption capability of the deoxidizing multilayered film 15was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 40 hours,concentration of the aldehydes was 15 ppm, and concentration of thecarboxylic acids was less than 0.25 ppm, which is the lower detectionlimit of the gas detector tube, and odor from the inside of the bag wasnot identified. The results are shown in Table 2.

Comparative Example 4

A multilayered film having m-LLDPE as the isolation layer (A), theoxygen absorbent resin composition 1 as the oxygen absorption layer(B1), and the oxygen absorbent resin composition 1 as the oxygenabsorption layer (B1) was produced by laminating them in this order byco-extrusion (co-extrusion temperature was 160° C.). The layerconstitution includes the isolation layer (A) with a thickness of about10 μm, the oxygen absorption layer (B1) with a thickness of about 20 μm,and the oxygen absorption layer (B1) with a thickness of about 20 μm, inthis order. Next, to the oxygen absorption layer (B1) side of themultilayered film produced, the oxygen barrier layer (D) with athickness of 12 μm, which is made of SiPET, was bonded by dry laminationwith the silica-deposited surface employed as the adhesive surface togive a deoxidizing multilayered film 16.

The oxygen absorption capability of the deoxidizing multilayered film 16was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film,” and as a result, deoxygenation time was 30 hours,concentration of the aldehydes was 52 ppm, and concentration of thecarboxylic acids was 8.5 ppm, and strong odor was identified. Theresults are shown in Table 2. Further, when the concentration of thealdehydes was measured, a gas detector tube for acetaldehyde(ACETALDEHYDE 92M (for medium concentration), manufactured by GastecCorporation) was used.

Comparative Example 5

A multilayered film having the acidic gas absorbent resin composition 1as the acidic gas absorbent isolation layer (Aa), the odor absorbentresin composition 7 as the odor absorption layer (Cx7), and the odorabsorbent resin composition 7 as the odor absorption layer (Cx7) wasproduced by laminating them in this order by co-extrusion (co-extrusiontemperature was 160° C.). The layer constitution includes the isolationlayer (A) with a thickness of about 10 μm, the odor absorption layer(Cx7) with a thickness of about 20 μm, and the odor absorption layer(Cx7) with a thickness of about 20 μm, in this order. Next, to the odorabsorption layer (Cx7) side of the multilayered film produced, theoxygen barrier layer (D) with a thickness of 12 μm, which is made ofSiPET, was bonded by dry lamination with the silica-deposited surfaceemployed as the adhesive surface to give a deoxidizing multilayered film17.

The oxygen absorption capability of the deoxidizing multilayered film 17was evaluated according to the “method 2 for evaluating the deoxidizingmultilayered film.” As a result, the deoxygenated state was not achievedeven after 150 hours from the start of the measurement. The results areshown in Table 2.

TABLE 2 Evaluation results according to the “method 2 for evaluating thedeoxidizing multilayered film” Concentration of Concentration ofDeoxygenation aldehydes carboxylic acids Layer constitution time*⁾ (h)(ppm) (ppm) Example 8 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 51 8 <0.25 Odor absorption layer (C1)/Barrierlayer (D) Example 9 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 55 10 <0.25 Odor absorption layer (C2)/Barrierlayer (D)/ Example 10 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 34 10 <0.25 Odor absorption layer (Cx4)/Barrierlayer (D) Example 11 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 40 10 <0.25 Odor absorption layer (Cx5)/Barrierlayer (D) Example 12 Acidic gas absorbent isolation layer (Aa)/Oxygenabsorption layer (B1)/ 40 15 <0.25 Odor absorption layer (Cx6)/Barrierlayer (D) Comparative Isolation layer (A)/Oxygen absorption layer (B1)/30 52 8.5 example 4 Oxygen absorption layer (B1)/Barrier layer (D)Comparative Acidic gas absorbent isolation layer (Aa)/Odor absorptionlayer (Cx7)/ >150 — — example 5 Odor absorption layer (Cx7)/Barrierlayer (D) *⁾Initial oxygen amount: 0.10 mL/cm²

As is clearly from Table 2, in deoxygenation starting from the initialoxygen amount of 0.10 mL/cm² (i.e., method 2 for evaluating thedeoxidizing multilayered film), Comparative example 4 in which adeoxidizing multilayered body that is not laminated with the odorabsorption layer (C1) containing an odor absorbent is used showed highconcentration of the aldehydes and the carboxylic acids as a odorouscomponent, and strong odor was produced. Meanwhile, in Comparativeexample 5 in which only the odor absorption layer (Cx7) containing anoxidizable thermoplastic resin was laminated and the oxygen absorptionlayer (B1) was not laiminated, the oxygen absorption capability wassignificantly decreased and the deoxygenated state was not achieved evenafter 150 hours from the start of the test.

On the contrary, in Examples 8 and 9 in which the acidic gas absorbentisolation layer (Aa), the oxygen absorption layer (B1), and the odorabsorption layer (C1 or C2) were laminated or Examples 10 to 12 in whichthe acidic gas absorbent isolation layer (Aa), the oxygen absorptionlayer (B1), and the odor absorption layer (Cx4, Cx5, or Cx6) containingthe oxidizable thermoplastic resin were laminated, the oxygen absorptioncapability was maintained while both the concentration of the aldehydesand the concentration of the carboxylic acids were suppressed and odorwas not identified. Further, compared to Examples 8 and 9 in which theodor absorption layer (C1) was laminated, Examples 10 to 12 in which theodor absorption layer (Cx4, Cx5, or Cx6) containing the oxidizablethermoplastic resin was laminated has shortened deoxygenation time, andthus this result indicated that the oxygen absorption capability isincreased more by having an oxidizable thermoplastic resin as thethermoplastic resin contained in the odor absorbent resin composition,which constitutes the odor absorption resin.

EXPLANATION OF REFERENCES

(A): Isolation layer

(B): The oxygen absorption layer, which is made of the oxygen absorbentresin composition (b)

(C): The odor absorption layer, which is made of the odor absorbentresin composition (c)

(D): The oxygen barrier layer

1. A deoxidizing multilayered body constituted by laminating at least:an isolation layer (A) that contains at least a thermoplastic resin; anoxygen absorption layer (B) which is made of an oxygen absorbent resincomposition (b) that contains an oxidizable thermoplastic resin and atransition metal catalyst; an odor absorption layer (C) which is made ofan odor absorbent resin composition (c) that contains a thermoplasticresin and an odor absorbent; and an oxygen barrier layer (D) whichcontains an oxygen barrier substance, in this order.
 2. The deoxidizingmultilayered body according to claim 1, wherein the odor absorbent resincomposition (c) is an odor absorbent resin composition (cx) thatcontains an oxidizable thermoplastic resin, a transition metal catalyst,and an odor absorbent.
 3. The deoxidizing multilayered body according toclaim 1, wherein the isolation layer (A) is an acidic gas absorbentisolation layer (Aa), which is made of an acidic gas absorbent resincomposition (a) that contains an acidic gas absorbent and athermoplastic resin.
 4. The deoxidizing multilayered body according toclaim 3, wherein the acidic gas absorbent contains a base compound. 5.The deoxidizing multilayered body according to claim 4, wherein the basecompound is magnesium oxide.
 6. The deoxidizing multilayered bodyaccording to claim 1, wherein the odor absorbent contains a hydrazinederivative, a urea derivative, or a guanidine derivative.
 7. Thedeoxidizing multilayered body according to claim 1, wherein the odorabsorbent is constituted by supporting a hydrazine derivative, a ureaderivative, or a guanidine derivative on a carrier.
 8. The deoxidizingmultilayered body according to claim 6, wherein the hydrazine derivativeis an aminoguanidine derivative and/or a hydrazine double salt.
 9. Thedeoxidizing multilayered body according to claim 1, wherein the oxygenabsorbent resin composition (b) further contains a photoinitiator. 10.The deoxidizing multilayered body according to claim 2, wherein the odorabsorbent resin composition (cx) further contains a photoinitiator. 11.The deoxidizing multilayered body according to claim 1, wherein theoxygen absorbent resin composition (b) further contains at least onecomponent selected from the group consisting of a photoinitiator, athermoplastic resin that is different from the oxidizable thermoplasticresin, and an additive, and the total compounding ratio of theoxidizable thermoplastic resin, the transition metal catalyst, and thecomponent is 100% by mass in the oxygen absorbent resin composition (b).12. A deoxidizing packaging container comprising at least in a partthereof, the deoxidizing multilayered body according to claim 1, whichis constituted by placing the isolation layer (A) on the inside of thecontainer.
 13. The deoxidizing multilayered body according to claim 1,wherein the oxidizable thermoplastic resin is 1,4-polybutadiene,1,2-polybutadiene, 1,4-polyisoprene, 3,4-polyisoprene, styrene butadienerubber, a styrene-butadiene-styrene block copolymer, astyrene-isoprene-styrene block copolymer, an ethylene/methylacrylate/cyclohexenyl methyl acrylate copolymer or a mixture thereof.14. The deoxidizing multilayered body according to claim 1, wherein theoxidizable thermoplastic resin is 1,2-polybutadiene.
 15. The deoxidizingmultilayered body according to claim 14, wherein 1,2-polybutadiene issyndiotactic 1,2-polybutadiene.